1. Field of Invention
This invention relates to pumps and, more particularly, to hydraulic or vacuum pumps for the movement of air or fluid through a pump with a birotational shaft.
2. Prior Art
The most widely used type of pump is the valve piston pump of which numerous constructions are known. Its disadvantages include the high cost of manufacture, the considerable work involved in carrying out repairs because of the valve and the associated crank mechanism which is necessary to convert the rotary movement piston mover into a rectangular reciprocating movement of the piston and the considerable space requirement.
A variety of rotary positive deplacement pumps not using a valve are known. Pumps having a single concentrically fitted rotor and a sliding valve seal have the disadvantages of a tendency to wear caused by the abrasive effect of the valve, the necessity for springs to be incorporated therein and, that the fluid path is along a single line. In addition, pumps with rotating valves and rotating blades display the appreciable effect of being liable to wear at their casing and blades because of the centrifugal forces acting on the blades.
U.S. Pat. No. 3,765,805 discloses a positive displacement double acting piston pump wherein the shaft drives the disk to which is pivotally secured a piston. The piston is connected to the pump casing, and on rotation of the disk, osculation of variable intensity occurs. The disk is sealed whereby the piston divides the casing into two chambers of variable volume. Fluid is displaced in this pump by rotation of the disk.
U.S. Pat. No. 4,406,121 discloses a rotary fluid device disclosing a multiple stage energized fluid flywheel contained within a housing. Pressurized fluid is discharged from the device to either a peripheral exhaust ring or an adjacent motor. The flywheel can operate using air, hydraulic fluid or other fluids.
U.S. Pat. No. 3,070,075 discloses a twin cylinder fluid motor with pendulum pistons. This motor acts as a hydraulic or pneumatic double acting twin cylinder motor.
A pump with a piston rod, construction is disclosed in Swiss Patent No. 86,916.
Hydraulic pumps as conventionally designed only pump fluid in one direction. While one directional shaft pumps are quite useful, great damages occurs to the pump if the direction of flow of the fluid is reversed. This reversal can cause the pump to burn out. Also, improper installation of a one directional pump can cause problems.
While some birotational pumps have been designed, they are complicated and suffer the additional problems of high cost and complicated design.
Accordingly, it is an object of this invention to produce a birotational pump for use in a hydraulic mechanism.
It is a further object of this invention to produce a birotational pump where no casting of the parts is required.
It is an additional object of this invention to product a fluid pump which is birotational.
It is a still further object of this invention to produce a birotational pump which is easy to repair, easy to manufacture and reliable.
These and other objects and features of the present invention will become apparent from a consideration of the following description and the accompanying drawings in which a selective example of the construction of the invention is set forth to illustrate the invention.